JPH0340661A - Method and apparatus for picture recording - Google Patents

Abstract

PURPOSE:To decrease a change in picture quality even when the recording speed is increased by deciding recording data at present point of time from a picture element data at present time, preceding M-set of picture element data from the present time, and preceding M-set of recording data from the present time. CONSTITUTION:A programmable array logic(PAL) 85 receives a picture element data DT0 at present time from a FF 82, preceding picture element data DT1, DT2 from the present time, preceding recording data HT1-HT6 from the present time, and a 3-bit speed mode signal (SPEED) sent from a CPU and outputs a recording data (picture element data to be actually recorded) OD1/or OD2/ at present time. Moreover, the similar function as that of the PAL 85 is attained by using a ROM. Then the recording data OD1/OD2/ are recording data P- DATA by a NOR circuit 86.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image recording method and apparatus, and more particularly to an image recording method and apparatus for recording images such as characters, figures, and various signal waveforms according to recording data.

[Prior Art] Conventionally, this type of apparatus has recorded images at a relatively slow and fixed paper feeding speed due to cost considerations. Now, assuming paper feed speed = 5 mm/S, resolution = 20 lines/mm, 1 loms in the paper feed direction.
It is sufficient to record in pixel ratio.

By the way, there is a demand for increasing recording speed without increasing cost. However, in the above case, if the paper feeding speed is increased by 10 times, for example, it becomes necessary to record at a rate of 1 pixel every 1 ms in the paper feeding direction. For this reason, the black density per pixel changes, and the overall image quality changes. Furthermore, when a thermal type print head is used, for example, a reduction in the life of the head due to continuous overheating becomes a problem.

[Problem to be Solved by the Invention 1] The present invention has been made in view of the above-mentioned prior art, and its purpose is to provide an image recording method and an apparatus for the same in which there is little change in image quality even when the recording speed is increased. It is about providing.

Another object of the present invention is to provide an image recording method and an apparatus for the same, which reduces the burden on the print head even when the recording speed is increased.

[Means for Solving the Problem] In order to achieve the above object, the image recording method of the present invention has the following features:
In an image recording method in which images are sequentially recorded according to recorded data, current recorded data is determined based on current pixel data, N pieces of pixel data that go back in time from the current time, and M pieces of recorded data that go back in time from the current time. This is the summary.

Further, in order to achieve the above object, the image recording apparatus of the present invention includes a printing element that sequentially records images according to recording data, and N pixel data DT1 to DTN from the present time to the past regarding the printing element and from the present time to the past. M going back to the past
storage means for sequentially storing recording data HTI to HTM, and when recording by the printing element, current pixel data DTO, N pixel data D1 to DTN read from the storage means and M records; Data HTI~H
The outline thereof is to include a determining means for determining the current recorded data HTO based on the TM.

Preferably, the determining means determines the current recording data HTO in accordance with the recording speed.

Also preferably, the determining means HT0=DT0*DT 1/*DT2/*HTl/*H
T2/ However, the outline is that / is provided with a logical operand indicating negative logic.

Preferably, the determining means has a logical operation term of HTO=DTl *DT2/*HT2/where / indicates negative logic.

Also preferably, the determining means comprises: HT0=DT0*DT2*HT2/ However, / indicates negative logic Its outline is that it has logical operands.

Preferably, the determining means is provided with a logical operation term: HTO=DT1/*DT2*HT3/, which functions when the recording speed is high.

[Operation] In the above configuration, the printing element sequentially records images according to recording data. On the other hand, the storage means stores N pixel data DT1 to D regarding the printing element dating back to the past from the present time.
TN and M pieces of recorded data HTI dating back to the past from the present time
~Sequentially store HTM. The determining means selects the current pixel data DTO and the N pixel data DTI read from the storage means when recording by the printing element.
- Determine the current recording data HTO based on DTN and M (specific three recorded data HT1 to HTM. Preferably, the determining means determines the current recording data HTO according to the recording speed.

[Description of Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram of an image recording apparatus to which the image recording method of the embodiment is applied. In the figure, 1 is a CPU, which performs main control of the embodiment device.

2 is a ROM, which stores various fixed information.

For example, 2-1 is a program storage area, and the CPU
1 stores a control program (not shown) to be executed. 2-2 is a character generator (CG) storage area, which stores binary pattern information corresponding to code information such as characters and graphics. As an example of this binary pattern information, 2-3 is grid pattern information, and the CPU
1 can develop a square grid pattern in the image memory 7 by arranging a plurality of such grid pattern information 2-3.

3 is a RAM, which the CPUI uses as a work area. Further, the RAM 3 temporarily stores code information such as characters, figures, and measurement signals to be recorded. These code information are sent from various remote medical measurement devices (not shown). 4 is a console (C3L), which includes switches, displays, etc. necessary for operation. 5 is a communication line (for example, LAN), which is connected to various remote medical measurement devices and the like. Reference numeral 6 denotes a communication control interface (DCI), which controls communication with medical measuring devices and the like via the communication line 5. 7 is an image memory (IM), R
Pattern information corresponding to each AM3 f-code information is developed into a bitmap. 8 is the heat controller (HC
), the image data (I-DATA) of IM7 is subjected to information processing according to the present invention, and the resulting recorded data (P
-DATA). Reference numeral 9 denotes a printer (PRN), which drives thermal head arrays 9-1 arranged vertically in parallel in accordance with P-DATA from the heat controller 8, and records an image on recording paper by a so-called rusk method.

10 is a common bus for the CPU 1.

FIG. 2 shows the countries of block construction of the heat controller 8 of the embodiment. In the figure, 81 is a parallel-serial converter, which converts, for example, 8-bit parallel I-DATA into serial data DT in accordance with a clock signal (not shown).

A flip-flop (FF) 82 sequentially stores serial data DT and outputs current pixel data DTO. 83 is a RAM, l of the thermal head 9-1
For each element, two pieces of pixel data DT dating back to the past from the current time
I and DT2, as well as 6 pieces of recorded data dating back to the past (data actually recorded in the past) HTI to HT
Remember 6. In addition, the address input of RAM83 is HAO.
There are a total of 11 bits from O to HAIO, and by incrementing this address to address O to 2047 in synchronization with the clock signal, the past information (8 bits each) of each of the printing elements for a total of 2048 pieces is sequentially read out. and refresh memory. A latch (LATCH) 84 temporarily stores past data read from the RAM 83.

85 is a programmable array logic (PAL), which receives the current pixel data DTO, RA from FF82.
Pixel data DTI, DT2 read from M83 from the present time to the past, and recorded data H from the present time to the past
The current recording data (pixel data to be actually recorded) ODI/
Or output OD2/. Note that functions equivalent to those of the PAL85 can also be configured with a ROM. Next, these recorded data ODI/, OD2/ are NORed by a NOR circuit 86.
and becomes recording data P-DATA. Also, this P-
DATA is also called current recorded data HTO. 8
Reference numeral 7 denotes, for example, an oven collector type buffer circuit (BUF), which updates the data stored in the RAM 83. That is, in order to read past data at the next point in time for the same printing element, the current pixel data DTO, DTI is used as the past pixel data DTI, DT2.
and the current recorded data HT O-HT
5 as past recorded data HTI to HT6 in RAM83
Update the stored data.

Figure 3 shows the programmable array logic (
2 is a conceptual diagram illustrating information processing in PAL) 85. FIG. In the figure, X is the direction in which the recording paper advances; for example, 4
It has a resolution of 0 dot/mm. Also, Y is 172
This is the direction in which eight thermal head elements are lined up in a row, and each element is lined up at a pitch of, for example, 8 dots/mm.

In this way, by setting the resolution to the relationship X>Y, recording dots in the X direction corresponding to the black l bit of pixel data can be recorded at different recording speeds (for example, medium speed = 25 mm/S, high speed = 50 mm/S). The black density is varied within the range of 2 to 4 dots depending on the image quality (S), and as a result, the black density given to the eye is made uniform.

FIG. 3 shows 99th to 101st thermal head elements 99 to 101. Now, attention is paid to information processing regarding the 100th thermal head element 100.

The pixel data (recording data) to be actually recorded is HTO. However, do you actually set HTO=O (white dot)?
TO=■ (black dot) is determined by the past pixel data DTI, DT2 read from the current pixel data DTO1RAM83, and the past recorded data HTI-HT6,
Also, the recording speed mode signal (S
'PEED) is determined by the following logical formula.

When mode signal = 0 (high speed), term ODI/
= DTI/Book DT2*HT3/
... B mode signal = 0 or l
(Medium speed) Term QD2/= DTO umbrella DT2*
HT2/...
・D+ DTI/*DT2*HT2/
...F+ DTl*DT2/*HT2/
...G+ DTO*DT1/*DT2/*
HT1/*HT2/...H10 DTO/Monday D
TI/*DT2/ *HT1*1 (72 pieces) IT3*HT4/*HT5/*
HT6/... ■That is, mode signal = O (high speed)
In the case of B.

Each logical operation term of D, F, G, H, and I functions, and when the mode signal = 1 (medium speed), F, G.

Each logical operator of H and I functions.

It should be noted that each of the above logical operation terms takes into consideration the influence of the resolution, recording speed, etc. of this embodiment on visual perception. resolution,
If conditions such as recording speed change, the logical operation terms may also change.

here, The above logical formula is shown in Table 1. It is easier to use if it is written as shown in Table 2.

Table 2゜OD2/=1 (mode signal = O or l) Figures 4 to 9 show the functions of each logical operation term in the programmable array logic (PAL) 85 of the embodiment.
FIG.

First, in Figure 4, a series of pixel data is "...0O1000...
・" indicates the case where the part is printed at high speed. That is,
In this case, the central pixel data = 1 is isolated surrounded by a large number of O's before and after it, and must be recorded at high speed.

Therefore, we decided to increase the recorded data for black. First t=5
At the point in time, the H term is satisfied and the recorded data becomes 1. That is, the H term is a term that captures the point in time when the pixel data changes from OO to 1 and sets the recorded data to 1. However, it is required that the recorded data at least at the previous time point of t=3.4 was O. Next, at the time of t=6, the G term is satisfied and the recorded data becomes 1. That is, in this case, the G term is 001 by extending the black dots recorded in the order of 001 by one dot.
This is the term to make it 1. Although this increases the visual black density somewhat, it is still not sufficient for high-speed recording.

Next, at the time of t=7, the B term is satisfied and the recorded data becomes l.

However, item B only works during high-speed printing. That is, the B term is
In this case, the black dots recorded in the order of 0011 are further extended by one dot to become 00111. This allows a group of isolated black recording dots to be clearly identified. Next, at the time of t=8, the first term is satisfied and the recorded data is 1
become.

However, in order for the first term to be satisfied, it is necessary that the recorded data at least at the previous time point of t=2 was O. In other words, the first term is, in this case, when O is recorded even at t=2, the black dot is further extended by l dots to become 000111.1.
This is the term to In this way, by changing the number of extended black dots depending on how long white dots have been recorded continuously in the past, the group of black dots to be recorded is further made clearer.

In Figure 5, the pixel data is "...001000..."
This shows the case where the part is printed at medium speed. That is, in this case, since recording is performed at a medium speed, one recorded black dot itself has a somewhat high density. Therefore, there is no need to increase the amount of black recording data. First, at the time t=5, the H term is satisfied in the same way as above, and at the next time t=6, the G
Satisfies the terms. Therefore, the recorded data so far is 001
Becomes 1. However, at the next time point t=7, since high-speed recording is not performed, term B is not satisfied. Furthermore, at the next time t = 8, the B term was not satisfied at the previous time t = 7, so
Item 1 is not satisfied.

Therefore, in the case of medium speed, the recorded data has a pattern of 001100, and as a result, the black density given visually is made uniform.

In Figure 6, a series of pixel data is “...001010101
0...'' is printed at high speed. In this case, we want to reproduce without losing the density pattern in which white and black pixels alternate in the middle. Moreover, since it is a high-speed recording, it is necessary to make only the first 001 part clear. In this case as well, in the same way as above, the H term is satisfied at the time of t=5,
At the time of t=6, the G term is satisfied. Therefore, the recorded data becomes 0011 first. At the next time point t=7, high-speed recording is being performed, so the B term is satisfied and the black dot is further extended. However, at the next time t=S, the pixel data DT part is 0.
10, which indicates that the pixel data DTO=1 at the previous time t=5 was not isolated within a considerable range before and after it, and therefore does not satisfy the first term. Also, at the next time t = 9, a black dot was recorded at the time t = 7 two years before that, so here it is necessary to secure a white dot in order to maintain the black and white density pattern. . Therefore, the recorded data so far is 0011100
become. At the next time t=10, a white dot is recorded at the time t=8 two years before, so the G term is satisfied and the recorded data becomes l. At the next time point t=11, since high-speed recording is being performed, term B is satisfied and the black dot is further extended. Therefore, in the case of high speed, the recorded data is 0011100110
As a result, the same density pattern as the original pixel data arrangement is visually presented.

In Figure 7, the pixel data is “...001010101
0...'' is printed at medium speed. Similarly, the H term is satisfied at t=5, and the G term is satisfied at t=6. Therefore, the recorded data is first 001
Becomes 1. However, at the time of t=7, medium-speed recording is being performed, so item 8 is not satisfied. Furthermore, at the time of t=8, since a black dot was recorded at the time of t=6, which is two points before that, a white dot is secured here. Therefore, the recorded data up to now is 001100. Furthermore, at the time of t=9, part 2
Since a white dot was recorded at the previous time t=7, D
The term is satisfied, and the recorded data becomes l. At the next time t=lo, a white dot is also recorded at the time t=8, which is two years before, so the G term is satisfied and the recorded data becomes 1.

Therefore, in the case of medium speed, the recorded data is 001100110
As a result, the same density pattern as the original pixel data arrangement is visually presented.

In Figure 8, a series of pixel data is "...001111111
1...'' is printed at high speed. In this case, all the dots become black from the middle, so it is necessary to prevent the thermal head element from overheating. Therefore, the record of the black dot will be postponed. Similarly, at the time of t=5.6, the H and G terms are satisfied, and the recorded data thus far becomes 0O11. At the next time point t=7.8, black dots are recorded at each time point two times before t=5.6, so the white dots are checked here.

Therefore, the recorded data up to now is 001100.

At the next time point t=9.10, white dots are recorded at each time point two times before t=7.8, so each of them satisfies the D term. Therefore, the recorded data so far is 0011001
Becomes 1. In this way, in the case of high speed, the recorded data is 00
The arrangement is 11001100 to prevent overheating of the thermal head element.

Similarly, in Figure 9, the pixel data is "...001111111
1...'' is printed at medium speed. In this embodiment, data processing in this case is similar to that shown in FIG. 8 to prevent overheating of the thermal head element.

Note that each logical operation term shown in the above-mentioned embodiment is only an example. That is, according to the above-mentioned idea of the present invention, various other logical operands can be used in accordance with the purpose of making the recording density uniform under various recording speeds and/or reducing the burden on printing elements such as thermal head elements. can be configured and added to the embodiment device. For example, in the above embodiment, as a result of taking into consideration prevention of overheating of the thermal head, the resulting recording pattern is the same when printing a portion with pixel data of "...0011111111..." at high speed and when printing at medium speed. However, it is not limited to this. In addition, for example, the recording pattern for high speed is 0011101110, and the recording pattern for medium speed is 001100.
It may be set to 1100.

Further, in the above embodiment, the pixel data and the recording data are binary, but the present invention is not limited to this. Even when the pixel data and recording data are multivalued, the logic of whether or not to record the pixel of interest according to the present invention is applicable.

[Effects of the Invention] As described above, according to the present invention, excessively dark areas are made thinner and excessively thin areas are made darker, so that even if the recording speed increases, there is little change in image quality. Furthermore, even if the recording speed increases, the load on the print head is reduced, so the life of the print head is extended.

[Brief explanation of drawings]

FIG. 1 is a block configuration diagram of an image recording apparatus to which the image recording method of the embodiment is applied. FIG. 2 is a block diagram of the heat controller 8 of the embodiment. FIG. 3 is a block diagram of the programmable array logic (
4 to 9 are diagrams explaining the functions of each logical operation term in the programmable array logic (PAL) 85 of the embodiment. In the figure, 1... CPU, 2... ROM, 2-1...
Program storage area, 2-2...Character generator (CG) storage area, 2-3...Grid pattern information, 3...RAM, 4...Console (CS)
L), 5... Communication line, 6... Communication control interface (DCI), 7... Image memory (IM)
8... Heat controller (HC) 9... Blink (PRN), 9-1... Radar array to thermal. Distance mode O Distance mode 1 Speed mode O Fig. Speed mode Fig. 7 Distance mode ○ Trace mode 1

Claims (7)

[Claims] (1) In an image recording method in which images are sequentially recorded according to recorded data, the current pixel data, N pieces of pixel data that goes back to the past from the current time, and M pieces of recorded data that goes back to the past from the current time are used to record the current picture. An image recording method characterized by determining recording data. (2) A printing element that sequentially records images according to recording data; N pieces of pixel data DT1 to DTN that go back to the past from the current time and M pieces of recording data HT1 to HTM that go back to the past from the current time about the printing element. a storage means for sequentially storing; upon recording by the printing element, current pixel data DT0, N pixel data DT1 to DTN and M recorded data HT1 to HTM read from the storage means;
An image recording apparatus characterized by comprising determining means for determining current recording data HT0. (3) The image recording apparatus according to claim 2, wherein the determining means determines the current recording data HT0 according to a recording speed. (4) The image according to claim 3, wherein the determining means includes a logical operation term: HT0=DT0*DT1/*DT2/ *HT1/*HT2/, where / indicates negative logic. Recording device. (5) The image recording apparatus according to claim 3, wherein the determining means includes a logical operation term: HT0=DT1*DT2/*HT2/, where / indicates negative logic. (6) The image recording apparatus according to claim 3, wherein the determining means includes a logical operation term: HT0=DT0*DT2*HT2/, where / indicates negative logic. (7) The image recording apparatus according to claim 3, wherein the determining means includes a logical operation term: HT0=DT1/*DT2*HT3/, which functions when the recording speed is high.